1. Field of the Invention.
This invention relates to powered overhead garage doors, and in particular to a system that will automatically open or close the garage door at the appropriate time and ensure that the garage door will not be inadvertently left open for any reason.
2. Description of the Prior Art
Powered overhead garage doors, equipped with an electric motor to open or close the door by radio control units (receiver and transmitter), or by pushbutton switch on the garage wall, have gained popularity over the past decade. While the system works quite satisfactorily for some time, there are problems of unintentional opening by stray radio signal, or by electromagnetic storms, or by electrical power fluctuations. The problem occurs probably more often when the driver simply forgets to depress the control button to close the garage door because of an emergency he has to attend to, or the traffic on the street he is backing into, or a minor illness, or simply because of the joy of getting home after a stressful day at work.
The need of an automatic garage door control device is evidenced by the numerous patents issued in this field. Some current U.S. Patents in this area include U.S. Pat. Nos. 4,035,702; 4,364,003; and 4,463,292. These proposals attempt to close the garage door after it has been opened for a selected time interval either by mechanical or electronic means.